Tntliience of Corpus lutcinn Hxtracts upon Pltiiii Muscle 9 



caus''<l a contraction of tetanic cliaractcr sliowin;; a dctiniti' increasf of tone 

 which histed lor a few minutes (ti«;. 7). 



Fici. 7. — KHect of corjius hiteuiii extract iij)oii tlie coiiliactioii <>f tin- rabbit's uterus ^in situ): 

 10 c.c. of a 1 ])er cent, extract of dried corpus luteuru was injected intravenously. This jiro- 

 duced at first a contraction of a somewhat prolonged character. 



Experiments upon the Cat'.s Uterus. 



A few experiments were made with the cat, one upon a pregnant uterus, 

 the rest non-pregnant. The usual result was as with the rat, increase of 

 tone, both with the fresh uterus and with that which had been kept in the 

 ice-chest, although to a much less extent in the latter case. The increase 

 of tone might be accompanied by acceleration of the rhythmic movements. 

 In one of the experiments there was diminution of tone. The increase of 

 tone is shown in fig. 8 ; diminution in fig. 9. 



Experiments upon the Dog's Uterus. 



Only one experiment was made ; upon a bitch's uterus. In this case 

 there was both an increase of tone and an increased rate of frequency of 

 the rhythmic contractions (fig. 10). 



Experiments upon the Uterus of the Guinea-pig. 



Four experiments were made on the guinea-pig, all on non-pregnant 

 animals. The result was a very great increase of tone with a tetanic 

 character of the rhythmic contractions, which showed almost complete 

 fusion. On substituting ordinary Locke there was at once great diminu- 

 tion of tone, followed by large rhythmic movements. 



Experiments upon Plain Muscle other than that of Uterus. 



Intestine of Rat. — A number of experiments — ten in all — were 

 made upon pieces of the jejunum of the rat removed from just below 

 the duodenum and placed in Locke solution. The pieces were emptied of 

 their contents, washed with Locke solution, tied at both ends with thread, 



